New Api application that I created

import uuid
from abc import ABCMeta, abstractmethod, ABC
from database import Database


class Model(metaclass=ABCMeta):
    collection = "model"

    def __init__(self, _id=''):
        self._id = _id or uuid.uuid4().hex

    @abstractmethod
    def to_json(self):
        raise NotImplementedError

    @classmethod
    def all(cls):
        return [cls(**item) for item in Database.all(cls.collection)]

    def save_to_db(self):
        Database.insert_one(self.collection, self.to_json())

    @classmethod
    def fine_one_by_id(cls, _id):
        item = Database.find_one_by_id(cls.collection, _id)
        return cls(**item)

    @classmethod
    def fine_one_by_name(cls, name):
        item = Database.find_one_by_name(cls.collection, name)
        return cls(**item)

    @classmethod
    def delete_one(cls, _id):
        if cls.fine_one_by_id(_id):
            Database.delete_one(cls.collection, _id)

    @classmethod
    def filter(cls, **kwargs):
        return [cls(**item) for item in Database.filter(cls.collection, **kwargs)]


class Category(Model, ABC):
    collection = "food_category"

    def __init__(self, name='', *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.name = name
        pass

    def to_json(self):
        return {
            '_id': self._id,
            'name': self.name
        }


class Food(Model, ABC):
    collection = "food"

    def __init__(self, name='', per100grams=0, cals_per100grams=0, kj_per100grams=0, category_id='', *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.name = name
        self.per100grams = per100grams
        self.cals_per100grams = cals_per100grams
        self.kj_per100grams = kj_per100grams
        self.category_id = category_id
        pass

    def to_json(self):
        return {
            '_id': self._id,
            'name': self.name,
            'per100grams': self.per100grams,
            'cals_per100grams': self.cals_per100grams,
            'kj_per100grams': self.kj_per100grams,
            'category_id': self.category_id
        }

from pymongo import MongoClient


class Database:
    url = "url_to_mongo_db"
    client = MongoClient(url)
    db = client.get_database()

    @classmethod
    def insert_one(cls, collection, item):
        cls.db[collection].insert_one(item)
        pass

    @classmethod
    def find_one_by_id(cls, collection, _id):
        return cls.db[collection].find_one({'_id': _id})

    @classmethod
    def find_one_by_name(cls, collection, name):
        return cls.db[collection].find_one({'name': name})

    @classmethod
    def delete_one(cls, collection, _id):
        cls.db[collection].delete_one({'_id': _id})

    @classmethod
    def all(cls, collection):
        return cls.db[collection].find({})

    @classmethod
    def filter(cls, collection, **kwargs):
        return cls.db[collection].find(kwargs)

from flask import Flask, make_response, jsonify

from models import Category, Food

app = Flask(__name__)


@app.route('/')
def index():
    return 'WELCOME TO FOOD CALORIES API'


@app.route('/categories/all')
def categories():
    all_categories = [category.to_json() for category in Category.all()]
    return make_response(jsonify(all_categories))


@app.route('/categories/<category_name>')
def get_category_by_name(category_name):
    selected_category = Category.fine_one_by_name(category_name)
    return make_response(jsonify(selected_category.to_json()))


@app.route('/categories/<category_name>/foods')
def get_foods_by_category_name(category_name):
    selected_category = Category.fine_one_by_name(category_name)
    selected_foods = [food.to_json() for food in Food.filter(category_id=selected_category._id)]
    return make_response(jsonify({'category': selected_category.to_json(), 'foods': selected_foods}))


@app.route('/foods/all')
def foods():
    all_foods = [food.to_json() for food in Food.all()]
    return make_response(jsonify(all_foods))


@app.route('/foods/<food_name>')
def get_food_by_name(food_name):
    selected_food = Food.fine_one_by_name(food_name)
    return make_response(jsonify(selected_food.to_json()))


@app.route('/foods/sorted-by-kj')
def sort_food_by_kj():
    selected_food = [food for food in Food.all()]
    selected_food.sort(key=lambda food: food.kj_per100grams)
    sorted_foods = [food.to_json() for food in selected_food]
    return make_response(jsonify(sorted_foods))


@app.route('/foods/sorted-by-cals')
def sort_food_by_cals():
    selected_food = [food for food in Food.all()]
    selected_food.sort(key=lambda food: food.cals_per100grams)
    sorted_foods = [food.to_json() for food in selected_food]
    return make_response(jsonify(sorted_foods))


if __name__ == '__main__':
    app.run(debug=True)